A method for modulating the spray concentration of a plasma air disinfector

Abstract

The present invention discloses a method for modulating the spray concentration of a plasma air disinfector, by setting an ion energy transfer function f ( t ) is used as the input function, which is also the injection modulation function. It can solve the problem of uneven concentration at far and near distances in plasma injection disinfection. The function is an exponential decay function that is strong at first and then weak. It is set according to the attenuation speed of ions in the air. The ions are injected in a non-uniform form. By setting the time sequence and space of ions to meet the safety standard of the maximum safe space ion energy, a plasma injection space distribution model is constructed, and the ion concentration distribution curve along the path and the comparison diagram of the plasma concentration time domain distribution and space distribution are calculated. The time domain concentration distribution function, the theoretical concentration distribution function ignoring consumption, and the actual concentration distribution after consumption can be obtained. Accurate modulation of ions can completely solve the safety problems caused by uneven concentration.

Description

Technical Field

[0001] The invention relates to the field of plasma technology, in particular to a method for modulating the spray concentration of a plasma air disinfector. Background Art

[0002] With the rapid economic and social development of recent years, the resulting health issues have received widespread attention. The global environment has also taken its toll, particularly on the Earth's atmosphere, which is subject to varying degrees of pollution. This pollution includes, but is not limited to, large particles like dust, small particles like smog, bacteria and viruses harmful to life, and impurities that affect human chemical industry control activities. This is particularly true for coronaviruses. Large, enclosed public spaces like hospitals, subway stations, buses, and high-speed rail stations, where large crowds facilitate the growth and spread of viruses and bacteria, are particularly vulnerable. Therefore, ensuring the air quality of these large public spaces is particularly important. Existing air disinfection equipment increases ion energy to meet both disinfection effectiveness and human safety. High-speed ions excite air molecules, generating a large amount of plasma. This ionization destroys and kills most viruses in the air within the space. Before disinfecting the air, the ions are sprayed. However, this spraying process results in uneven ion concentrations at different distances, which can affect both safety and disinfection effectiveness within the space. Summary of the Invention

[0003] The present invention aims to overcome the problems of low safety and disinfection effectiveness caused by uneven ion injection in plasma air disinfectors in the prior art, and provides a method for modulating the injection concentration of a plasma air disinfector to modulate the ion injection concentration so as to ensure disinfection effectiveness and safety for people in the ion disinfection space.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for modulating the spray concentration of a plasma air disinfector comprises the following steps:

[0006] Determine the full-space ion energy EIS , spatial ion density n , calculate the ion energy transfer function f ( t ), plasma injection concentration function n i ( t );

[0007] Research to determine safety standards, that is, the maximum safe space ion energy density allowed E STD ;

[0008] Derived spatial ion concentration distribution process; calculated ion concentration in the air based on spatial ion concentration distribution process n ( x );

[0009] Calculate the space standard concentration based on the ion concentration in the air and the determined safety standard;

[0010] The initial velocity of the ejected ions is set, and the ion source adopts non-uniform injection. The above content is modeled and assumed to obtain the position where the front end of the ions arrives at different times after being ejected into the air, and the time domain distribution and spatial distribution of the ion concentration are obtained. The spatial ion concentration is calibrated to determine the time domain concentration distribution function, the theoretical concentration distribution function ignoring consumption, and the actual concentration distribution after consumption.

[0011] The present invention sets the ion energy transfer function f ( t ) is used as the input function, which is also the injection modulation function. It can solve the problem of uneven concentration at far and near distances in plasma injection disinfection. The function is an exponential decay function that is strong at first and then weak. It is set according to the attenuation speed of ions in the air. The ions are injected in a non-uniform form. By setting the time sequence and space of ions to meet the safety standard of the maximum safe space ion energy, a plasma injection space distribution model is constructed, and the ion concentration distribution curve along the path and the comparison diagram of the plasma concentration time domain distribution and space distribution are calculated. The time domain concentration distribution function, the theoretical concentration distribution function ignoring consumption, and the actual concentration distribution after consumption can be obtained. Accurate modulation of ions can completely solve the safety problems caused by uneven concentration.

[0012] Preferably, the ion energy transfer function f ( t ) is generated by the ion source through the non-uniform injection form into the disinfection space, which is equivalent to the input function, indicating the amount of ion energy transferred per unit time, and the unit is eV / s , which is determined by the ion carrying energy and ion body flow rate;

[0013] ;

[0014] in, is the ion carrying energy, in units of eV ; is the plasma flow rate, in units of m 3 / s ;

[0015] Ion Energy Transfer Function f ( t ) is an input function, which serves as an ejection modulation function of the entire ion ejection source to modulate the ions;

[0016] In the ion body injection concentration function, the ion source adopts a non-uniform injection form, and the ion body concentration ni Accepts a function with time as a variable modulation,

[0017] C m is the coefficient;

[0018]

[0019]

[0020]

[0021] Total space ion energy EIS Ion Energy Transfer Function f ( t ) is obtained by integrating over time.

[0022] As a preference, in the research to determine the safety standard, the safety standard is determined by the space ion energy density E characterization,

[0023]

[0024] n =1.6*10 12 , =0.3

[0025] n is the spatial ion density, Carrying energy for ions;

[0026] According to the safety standards determined by current research, the maximum safe space ion energy density allowed for use E STD <1.6*10 12 *0.3=0.5*10 12 eV / m 3 .

[0027] Since the amount of energy carried by ions itself cannot completely determine the safety and effectiveness of the space in which the ions are located, because, firstly, ions frequently collide and exchange energy with particles in the surrounding space and are in a state of rapid decay; secondly, the size of the ion concentration also plays an equally important role in the ion field, so the product of the two is used as the evaluation standard.

[0028] Preferably, the process of deriving the spatial ion concentration distribution includes the following:

[0029] Assume that the total number of ions ejected by the ion ejection source in time t is N ,Right now ;

[0030] Assume that the ion spray source obeys f ( t ) time modulation function law, the ejected ions are t Arrival time x = d location, in dx The ion jet source has a spray angle of ;

[0031] exist t The ion group that arrives at the spatial position at any moment is distributed in the cone area, and its volume , the concentration of ions in the air within its volume is calculated as follows:

[0032] ;

[0033] v To arrive x = d Ion velocity at position; is the coefficient, which is determined to be 7.6 by experiment.

[0034] Preferably, the model assumptions include the following:

[0035] Set the initial velocity of the ejected ions v 0. The ions move in a uniform deceleration motion for 10 s , ion migration stops and the speed drops to 0;

[0036] Determine the time-domain concentration distribution function ;

[0037] The model assumptions described also include the following;

[0038] Set the position where the front part of the ion will arrive at different times after being ejected into the air

[0039]

[0040]

[0041] In the formula is the acceleration of uniform deceleration motion.

[0042] As a preference, since the ions that start first reach the end point first, the frequency of the ion concentration distribution is opposite to the time sequence.

[0043] Therefore, the time domain distribution of ion concentration and the spatial distribution are compared according to the ion distribution. The starting point of time corresponds to the concentration focus of space, that is, the end point of ion migration; the maximum time value is also the concentration coordinate corresponding to the maximum hysteresis, that is, the coordinate origin, which is the position of the ion injection source. Therefore, the coordinate transformation is performed to n ( x ) in the calculation formula x For (10- x ),get

[0044] Theoretical concentration distribution function without consumption ;

[0045] Actual concentration distribution after consumption n ( x ) 实际 =1.6*10 12 / m 3 .

[0046] Therefore, the present invention has the following beneficial effects:

[0047] The present invention uses an ion source to input the disinfection space in the form of a jet, makes a model assumption for the ion jet, sets the input ion energy transfer function, that is, modulates the ions as the input jet modulation function, calculates the time domain concentration distribution function, the theoretical concentration distribution function ignoring consumption, and the actual concentration distribution after consumption, so that the ions in time and space can meet the maximum safe space ion energy density, which is the disinfection safety standard for the air. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Schematic diagram of the plasma jet spatial distribution model of this embodiment.

[0049] Figure 2 is the ion concentration distribution curve along the path of this embodiment.

[0050] Figure 3 3 is a comparison diagram of the time domain distribution and spatial distribution of plasma concentration in this embodiment.

[0051] Figure 4 3 is a schematic diagram of the calibration of the plasma spatial concentration distribution curve of this embodiment. DETAILED DESCRIPTION

[0052] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0053] Example:

[0054] This embodiment provides a method for modulating the spray concentration of a plasma air disinfector, using Figure 1The plasma injection method shown in the figure, the origin position is the ion injection source.

[0055] The present invention includes the following contents:

[0056] Determine the full-space ion energy EIS , spatial ion density n , calculate the ion energy transfer function f ( t ), plasma injection concentration function n i ( t );

[0057] Research to determine safety standards, that is, the maximum safe space ion energy density allowed E STD ;

[0058] Derived spatial ion concentration distribution process; calculated ion concentration in the air based on spatial ion concentration distribution process n ( x );

[0059] Calculate the space standard concentration based on the ion concentration in the air and the determined safety standard;

[0060] The initial velocity of the ejected ions is set, and the ion source adopts non-uniform injection. The above content is modeled and assumed to obtain the position where the front end of the ions arrives at different times after being ejected into the air, and the time domain distribution and spatial distribution of the ion concentration are obtained. The spatial ion concentration is calibrated to determine the time domain concentration distribution function, the theoretical concentration distribution function ignoring consumption, and the actual concentration distribution after consumption.

[0061] Preferably, the ion energy transfer function f ( t ) is generated by the ion source through the non-uniform injection form into the disinfection space, which is equivalent to the input function, indicating the amount of ion energy transferred per unit time, and the unit is eV / s , which is determined by the ion carrying energy and ion body flow rate;

[0062] ;

[0063] in, is the ion carrying energy, in units of eV ; is the plasma flow rate, in units of m 3 / s ;

[0064] Ion Energy Transfer Function f ( t) is an input function, which serves as an ejection modulation function of the entire ion ejection source to modulate the ions;

[0065] In the ion body injection concentration function, the ion source adopts a non-uniform injection form, and the ion body concentration ni Accepts a function with time as a variable modulation,

[0066] C m is the coefficient;

[0067]

[0068]

[0069]

[0070] Total space ion energy EIS Ion Energy Transfer Function f ( t ) is obtained by integrating over time.

[0071] As a preference, in the research to determine the safety standard, the safety standard is determined by the space ion energy density E characterization,

[0072]

[0073] n =1.6*10 12 , =0.3

[0074] n is the spatial ion density, Carrying energy for ions;

[0075] According to the safety standards determined by current research, the maximum safe space ion energy density allowed for use E STD <1.6*10 12 *0.3=0.5*10 12 eV / m 3 .

[0076] Since the amount of energy carried by ions itself cannot completely determine the safety and effectiveness of the space in which the ions are located, because, firstly, ions frequently collide and exchange energy with particles in the surrounding space and are in a state of rapid decay; secondly, the size of the ion concentration also plays an equally important role in the ion field, so the product of the two is used as the evaluation standard.

[0077] Preferably, the process of deriving the spatial ion concentration distribution includes the following:

[0078] Assume that the total number of ions ejected by the ion ejection source in time t is N ,Right now ;

[0079] like Figure 1 , the origin position is the position of the ion injection source, and the injection of the ion injection source obeys f ( t ) time modulation function law, the ejected ions are t Arrival time x = d location, in dx The ion jet source has a spray angle of ;

[0080] θ = 0.1 rad ;

[0081] α = 0.2 rad = 57.296° / rad × 0.2 rad =11.459°;

[0082] These ions will be distributed in a high- dx The volume of the micro-cone is dv = πx 2 θ 2 d x , where r = x θ ,

[0083] exist t The ion group that arrives at the spatial position at any moment is distributed in the cone area, and its volume , the concentration of ions in the air within its volume is calculated as follows:

[0084] ;

[0085] For simplicity, Assumption = 1 m 3 / s , v = 20 m / s , θ = 0.1, λ The experimental result shows that the concentration is 7.6. Based on safety and effectiveness, the standard concentration in space is

[0086]

[0087] v 0= at

[0088] v 0= 20

[0089] a = 20

[0090] t = 1.

[0091] Preferably, the model assumptions include the following:

[0092] Set the initial velocity of the ejected ions v 0. The ions move in a uniform deceleration motion for 10 s , ion migration stops and the speed drops to 0;

[0093] Determine the time-domain concentration distribution function ;

[0094] Find the following typical data about n(t) and n(X) as shown in Table 1:

[0095] sheet

[0096] ()=n() 0 10 <![CDATA[2000×1.6×10 12 ]]> 0.25 4.4 <![CDATA[300 ×1.6×10 12 ]]> 0.5 7.5 <![CDATA[45 ×1.6×10 12 ]]> 0.75 9.4 <![CDATA[0.68×1.6×10 12 ]]> 1.0 0 <![CDATA[1.6×10 12 ]]>

[0097] At this time, the ion concentration distribution curve along the path is as follows Figure 2 As shown;

[0098] The model assumptions described also include the following;

[0099] Set the position of the ion front at different times after being ejected into the air:

[0100]

[0101]

[0102] In the formula is the acceleration of uniform deceleration motion.

[0103] As a preference, since the ions that start first reach the end point first, the frequency of the ion concentration distribution is opposite to the time sequence, such as Figure 3 As shown;

[0104] Therefore, the time domain distribution of ion concentration and the spatial distribution are compared according to the ion distribution. The starting point of time corresponds to the concentration focus of space, that is, the end point of ion migration; the maximum time value is also the concentration coordinate corresponding to the maximum hysteresis, that is, the coordinate origin, which is the position of the ion injection source. Therefore, the coordinate transformation is performed to n ( x ) in the calculation formula x For (10- x ),get

[0105] Theoretical concentration distribution function without consumption ;

[0106] Actual concentration distribution after consumption n ( x ) 实际 =1.6*10 12 / m 3 .

[0107] Finally, the injection modulation function is determined to be

[0108]

[0109]

[0110] n i ( t ) = 10 15 (2 -t 2 )(1 -t ) e -λt

[0111] The overall relationship is:

[0112] Time domain concentration distribution function ;

[0113] Ignore consumption concentration distribution function ;

[0114] Concentration distribution after consumption n ( x ) 实际 =1.6*10 12 / m 3 .

[0115] The spatial ion concentration was calibrated, and the results were as follows: Figure 4 shown.

[0116] The specific description of the present invention in the above embodiments is only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical engineers in this field may make some non-essential improvements and adjustments to the present invention based on the contents of the above invention, which fall within the scope of protection of the present invention.

Claims

1. A method for modulating the spray concentration of a plasma air disinfector, characterized in that: Includes the following: Determine the full-space ion energy EIS and spatial ion density n, and calculate the ion energy transfer function f(t), which is the product of the ion body injection concentration function, the ion carrying energy, and the ion body flow rate. The ion body injection concentration function n i (t), is the coefficient C m The product of e raised to the power of negative λt; The study determined the safety standard, that is, the maximum safe space ion energy density E allowed for use. STD ; Derive the spatial ion concentration distribution process; assume that the total number of ions N ejected by the ion ejection source within time t is f(t) time integral = N(t), assume that the ion ejection source ejection obeys the time modulation function of f(t), the ejected ions arrive at position x = d at time t and are distributed within the range dx, the ejection angle of the ion ejection source is α, the ion group is distributed in a conical area, calculate the volume of the conical area ΔV, and calculate the ion concentration n(x) in the air as the quotient of N(t) and ΔV; Calculate the spatial standard concentration based on the ion concentration in the air and the determined safety standard; The initial velocity of the ejected ions is set, and the ion source adopts non-uniform ejection. The above content is modeled and assumed to obtain the position of the front part of the ions at different times after being ejected into the air, and the time domain and spatial distribution of the ion concentration are obtained. The spatial ion concentration is calibrated to determine the time domain concentration distribution function, the theoretical concentration distribution function without consumption, and the actual concentration distribution after consumption. Determine the injection modulation function and modulate the ions.

2. A plasma air disinfector spray concentration modulation method according to claim 1, characterized in that: The ion energy transfer function f(t) is generated by the ion source inputting into the disinfection space in a non-uniform spray form, which is equivalent to the input function, indicating the amount of ion energy transferred per unit time, in eV / s, which is determined by the ion carrying energy and the ion flow rate; f(t)=εn i (t)ρ; Among them, ε is the ion carrying energy, the unit is eV; ρ is the ion flow rate, the unit is m 3 / s; In the ion body injection concentration function, the ion source adopts a non-uniform injection form, and the ion body concentration ni accepts a function C with time as a variable. m e -λt modulation, n i (t)=C m e -λt f(t)=εC m e -λt r ∫f(t)dt=EIS The full-space ion energy EIS is obtained by integrating the ion energy transfer function f(t) over time.

3. A plasma air disinfector spray concentration modulation method according to claim 1, characterized in that, The safety standard determined in the research is characterized by the space ion energy density E, E=nε n=1.6*10 12 ,ε=0.3 n is the spatial ion density, ε is the ion carrying energy; The maximum safe space ion energy density E allowed STD <1.6*10 12 *0.3=0.5*10 12 eV / m 3 .

4. A plasma air disinfector spray concentration modulation method according to claim 1, characterized in that: The process of deriving the spatial ion concentration distribution includes the following: Assume that the total number of ions ejected by the ion ejection source in time t is N, that is, ∫f(t)dt=N(t); Assume that the ejection of the ion ejector obeys the time modulation function f(t), the ejected ions arrive at the position x=d at time t, are distributed within the range dx, and the ejection angle of the ion ejector is α; The ion group that arrives at the spatial position at time t is distributed in the cone area, and the volume of the cone area is The concentration of ions in the air within its volume is calculated as follows: v is the ion velocity reaching the position x=d; λ is a coefficient determined by experiment.

5. A plasma air disinfector spray concentration modulation method according to claim 1, characterized in that: The model assumptions described include the following: Set the ejected ion initial velocity v0, the ions to uniform deceleration motion, last for 10s, the ion migration motion stops, and the velocity drops to 0; Determine the time domain concentration distribution function n(t) = 1.6*10 12 e 7.6(1-t) ; The model assumptions described also include the following; Set the position where the front part of the ion will arrive at different times after being ejected into the air x=20t-10t 2 x| t＝0.75 ＝20×0.75-10×0.75 2 ＝15-10×0.56＝15-5.6＝9.4 10t 2 -20t+x=0 Where a is the acceleration of uniform deceleration motion.

6. A plasma air disinfector spray concentration modulation method according to claim 5, characterized in that: The frequency of the ion concentration distribution is opposite to the time sequence. The time domain distribution of the ion concentration is compared with the spatial distribution. The starting point of time corresponds to the concentration at the end point of space, that is, the migration end point of the ion. The maximum time value is also the concentration coordinate corresponding to the maximum hysteresis, that is, the coordinate origin. The coordinate origin represents the position of the ion injection source. Therefore, the coordinate transformation is performed to replace x in the n(x) calculation formula with (10-x) to obtain the theoretical concentration distribution function ignoring consumption. Actual post-consumption concentration distribution n(x) 实际 =1.6*10 12 / m 3 .

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